You’re right.
I don’t think it would be wise for him to bring it up at all. It would backfire and get her the “outraged sympathy vote”.
How dare that mean old man embarrass this woman, see, I told you he was a misogynist!
IMO, he will limit his remarks to “she doesn’t have the strength or stamina”, as he has from the campaign start. I feel pretty sure DJT already knew what ails the Beast, from the beginning. He will play it smart, and let others (of which there will be many) speak about it.
Agreed, Trump should not bring it up at all. Now a friend of Trump’s might want to keep it in the news.